(Sorry if these were in the OP link and I didn’t see them - the site is unusable on mobile)
I have no idea how this would work in a practical sense - the image minification would be massive. It would be like looking through backwards binoculars at all time.
I'm shocked at how thin those lenses are. I'm at -11.5 diopter and my edges are already >1cm thick. It sounds like it's one lens set entirely inside another one? Even using 1.8 index material the thinness is really impressive. I bet the chromatic abberation isn't, though. It's not 1-to-1 but generally the higher the refractive index the lower the Abbe number, the more colors get split apart.
The concentric rings of increasing blurriness remind me of a Fresnel lens. I'm no optician and always found the physics of light rays confusing as heck so the only words I understand from the wikipedia aricle are "A Fresnel lens can be made much thinner than a comparable conventional lens, in some cases taking the form of a flat sheet." Maybe someone else can tell whether that's what's being used here? https://en.wikipedia.org/wiki/Fresnel_lens
The article says that they're biconcave, which means that the thinnest part of the lens is in the centre (similar to a red blood cell). For high-myopia lenses, they often remove the lens material away from the centre to limit the maximum thickness at the expense of reducing the field of view. The resulting surface is usually left unpolished, but the lens underneath will still bend light, resulting in the circular patterns you mentioned. In this case a very large amount of material is removed as they would be impossible to use with a conventional frame otherwise. The alternative would be to use glasses with very small lenses.
I don't think it's a Fresnel lens. Fresnel lenses have rather obvious rings and have poor optical qualities for most applications besides light sources, cheap slide projectors, and magnifying glasses.
Here, the "lens-within-a-lens" effect that you see is because, generally speaking, myopia lenses shrink the image. But this lens is so extreme that the image is shrunk into a small bubble in the middle. The ring-like structures around this bubble are due to internal reflections within the lens.
I am around -5 and it is stable; I think this is not far from the limit where wearing glasses starts to be annoying (chromatic aberration, distortions, ...).
I could consider lenses but I am always wondering how air conditioning and the fact that I cover my eyes with some plastic works long term (well, I am 52 so it may not be that of a concern, finally :)).
At some point I considered lasic surgery but wearing glasses still trumps the risk for me (this is really a personal opinion, I know people who are really happy with the change)
I got pissed off at wearing glasses and contact lenses for 30 or so years.
Things like fear of losing the glasses, transporting liquids everywhere you go and requiring some sort of sanitation. It's not compatible with an active lifestyle IMO.
I wasn't eligible for laser treatment so a few months ago I opted for what is essentially cataract surgery (Refractive Lens Exchange). I don't regret it, the freedom is great. Vision definitely isn't 20/20, and things look funny under certain lighting conditions, and your short-range vision is destroyed since your eye can no longer physically focus, but I'm glad I did it. I seem to have got lucky in that I don't need galsses for up-close stuff like looking at a monitor.
I recently had laser eye surgery and subsequently re-evaluated my relationship with glasses over the previous 15 years — obviously I was frustrated enough to get the surgery but hadn’t considered their impact holistically over my life.
My feeling is that glasses are annoying from -1, but their impact is tolerated as being able to see is a net gain.
If I had known of their existence beforehand I might have sought out Ortho-K lenses — you wear them whilst you sleep and then take them out for corrected vision during the day. They are more expensive than surgery in the long term (10+ years), but they are less invasive and might be something worth considering.
People who are very nearsighted have those weird sort of lens when viewed from the front it looks like they have a lens within a lens. The edges are very thick and it tapers down at the center.
According to https://en.wikipedia.org/wiki/Myopia#Degree more than -6 is already considered high, and this is more than 16x that. I wonder what the shape of his eyes is like for such an extreme case.
Yeah, I'm shocked at this. Before seeing this, my naïve guess for "how strong do you think glasses get" would have been in the range of -15 to -20. I've got a friend in the -8 ballpark and already thought that was surprising.
Yes, above 5-6 diopters is considered high myopia, since that's where the risks for retinal detachment, glaucoma, etc. already increase significantly due to the elongated eyeball.
With high myopia, the vertex distance [0] starts to play a big role. Basically, as an example, if someone needs -10D glasses, the eye just has around -8.75D of myopia [1] (when wearing contact lenses). This gap becomes larger the higher the diopters are.
Using the formula on [0], I think this person has around -46.5D of myopia, but needs -106D glasses due to the vertex distance.
Apparently "Jan Miskovic has had eye problems since he was a child. Her eye disorder is quite complex, not only suffering from myopia, she also suffers from amblyopia in both eyes, astigmatism, strabismus, and keratoconus. And every year, the ability to see from his eyes is always down 4 to 5 diopters." https://www.kaskus.co.id/show_post/614e138ffdaf1f458260070d/...
Which includes eyeball rugby shaped and bulging cornea.
Photos and a video of the lenses in glasses at the bottom of the article. They're as strange as the extreme diopter would suggest but it's great to give vision back to Jan and allow him to continue his photography.
I had relatively mild nearsightedness in the past. I look at those lenses and I'm having trouble even comprehending what the world would look like if you need a prescription like that. Is everything so out of focus it's all basically a singular colored blur? Or..?
Normal human lens is already +50. How is it possible
to have +150 eye? Even if the lens is perfect sphere it cannot be +150. The focal length would be 7 millimeters.
Correction:
The focal length of sphere = 3R/2. Assuming 2 mm lens radius, most extreme case would be 3 mm which means. +333 diopters.
Now correct that.
I had a funny thing producing a focal length of about 7mm the other day. I had a vitrectomy where they take out the middle bit of your eye and put in a gas bubble instead which gradually dissolves and is replaced by liquid. At one point when lying on my back so with the bubble against the lens it did that. You get some odd effects!
https://youtu.be/Bd6V61EAIbk
(Sorry if these were in the OP link and I didn’t see them - the site is unusable on mobile)
I have no idea how this would work in a practical sense - the image minification would be massive. It would be like looking through backwards binoculars at all time.